SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47e7e90e2a5de3ee68a8985e009780b2a66c74fa0cd72ff11d63d2f1d193a8d5' 
  AND token = 'HKIZ+vHBdXyCG96SrBoSg4aHsK4uBCgr+ETI2xzS9XU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}